Today I got to work fitting the left firewall sub panel. The inboard edge needed notched out to clear the center rudder pedal support bracket.

I also fabricated a spacer from 0.063 thick material to support the back side of the sub panel mounting bracket which is riveted to the the rudder pedal support bracket.

Aside: Is it just me or all these brackets getting confusing?

Another aside: When designing various pieces of equipment in my professional life (mechanical engineer), I've assigned a plethora of names to components such as "Left Side Gusset", or "Upper Support Bracket", etc., etc. On several occasions, I thought it might be fun to give a part a more personal name, like "Bob" or "Louise". :-)

After getting that notch ready, I decided to match drill the right side sub panel to final size (#19).

When fitting the left side panel, I realized that my notch wasn't deep enough. I had trimmed it 3/32 deep to account for the thickness of the rudder pedal bracket, but didn't realize I needed to also account for the thickness of the stiffener. No big deal. A bit of trimming and filing later, the notch was 5/32 deep.

The brake line mounting bracket needs to stick through this panel, so that left me with the problem of how to locate where I should cut a slot. I could see the scratches it left in the back side of the sub panel, so I circled the general area.

I decided to stick on a layer of plumbers putty to get an impression of the brake line bracket.

After positioning the panel and pressing down on the bracket, the putty had a nice impression where the slot needed cut.

I laid out the slot, drilled a 3/16 hole at each end, and did the rough cuts with a die grinder.

A bit of filing had the slot cleaned up.

Here's the bracket that sticks through the slot.

Oops. Looks like the bracket isn't long enough. Actually this wasn't a surprise. I could tell the bracket was going to need remade with a longer tab. The slot is in the right place, but needs to be a little longer on the right. It sort of looks a little too long on the left, but that's a good thing since the tab will be wider once I fabricate the new one (note the angle of the sides of the tab).

Slot extended on right side.